Excellent reviews, indeed.
I just returned from a week in the Seychelles, including stays at both Northolme and Labriz. Both are truly amazing properties, and I received nice gold upgrades at both (booked base rooms at each, received the beachfront w/ plunge pool @ labriz, and oceanfront @ Northolme). Both properties seemed to be at very low occupancy. Furnishings/fixtures at both were quite nice, but I think the Northolme edges out Labriz for the nicer rooms.
The activities available at Labriz trump the Northolme (more beaches, hikes, bikes, etc.).
I thought the dining options at Labriz were quite underwhelming and, frankly, not up to the standards of the rest of the property. Set your dining expectations low and do your best to focus on the other aspects of the property, and you'll be pleased overall. The food at Northolme, however, was MUCH better, so it is possible to put together a decent meal in the Seychelles.
The ferry to Labriz was a bit of a depressing experience. The seas were not terribly rough, but it was definitely not a smooth ride. I don't want to imagine what the ride would be like in rougher water. If you are prone to sea-sickness, plan accordingly. The boat itself was in no way luxurious or impressive. As a matter of making a first impression, there is a lot of room for improvement; but I certainly appreciate the practical considerations.
Service at both properties was very good. Staff seems genuinely eager to please, though I thought Labriz was much less polished/refined when it came to actually executing on the service.
Note that there is currently a large construction project occurring at Northolme. They are building a presidential villa and a handful of new villas w/ private pools. Others have complained of serious construction noise, though I can't say that we noticed it at all. If you're concerned about this (or even if you're not), be sure to request a room on the other side of the property, closer to the restaurants/pool/reception area.
Overall, two amazing hotels. Difficult to get to, but well worth the trip. We can't wait to go back.